Tom Lane wrote:
> "Gaetano Mendola" <mendola@gmail.com> writes:
>
>> On Fri, Jun 20, 2008 at 4:37 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> (Of course you realize that referencing any table at all in an
>>
>>> "immutable" function is probably a mortal sin...)
>>>
>
>
>> Yes Tom I know, in our case that table is a lookup table, noone update,
>> delete, insert data in it, so from my point of view it is like I have
>> declared a static array inside the function declaration.
>>
>
> No, you'd like to imagine that it is a static array, but that technique
> is just a foot-gun waiting to bite you. As an example, since pg_dump
> has no idea that that function has any dependency on the lookup table,
> there is nothing to stop it from trying to create the index before it's
> populated the lookup table.
>
> (I think it probably works for you at the moment because pg_dump tends
> to fill all the tables before creating any indexes, but the planned
> changes to support multi-threaded restores will certainly break your
> case.)
>
>
>
Purely static lookup tables can also often be replaced by enum types,
often with significant efficiency gains.
cheers
andrew
